The PTS®Enhanced Polymer Rail Sections™(ERS™) - M-LOK are lightweight low profile 1913rail sections, made out of one of the strongest and an EP series hallmark Dupont™Zytel High Performance Reinforced Polymer. The double chamfered ends reducesnagging and are comfortable to index against.Available in 5 different lengths: 3, 5, 7, 9 and 11slots.